The author is British: http://en.wikipedia.org/wiki/American_and_British_English_di...
"Companies are singular".
Which indeed they are, although staffed by multiple individuals.
The idea of a "corporate person" is much more recent, like 1880's, and I think started in the US.
From wikipedia:
In the late seventeenth century, Stewart Kyd, the author of the first treatise on corporate law in English, defined a corporation as,
"a collection of many individuals united into one body, under a special denomination, having perpetual succession under an artificial form, and vested, by policy of the law, with the capacity of acting, in several respects, as an individual, particularly of taking and granting property..."
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And don't be facetious, everyone knows the Dutch were very innovative during the slave trade.